Appearance of Hürthle cell carcinoma soon after surgical extirpation of Hürthle cell adenoma and follicular adenoma of the thyroid gland

Abstract

BackgroundHürthle cell neoplasms could be benign (Hürthle cell adenoma) or malignant (Hürthle cell carcinoma). Hürthle cell carcinoma is a rare tumour, representing 5% of all differentiated thyroid carcinomas. The cytological evaluation of Hürthle cell neoplasms by fine needle aspiration biopsy (FNAB) is complicated because of the presence of Hürthle cells in both Hürthle cell adenoma and Hürthle cell carcinoma. Thus, the preoperative distinction between these two entities is very difficult and possible only with pathohistological findings of the removed tumour.Case reportA 57-year old female patient was admitted at our Department, for investigation of nodular thyroid gland. She was euthyroid and FNAB of the nodules in both thyroid lobes were consistent of Hürthle cell adenoma with cellular atypias. After thyroidectomy the histopathology revealed Hürthle cell adenoma with high cellular content and discrete cellular atypias in the left lobe and follicular thyroid adenoma without cellular atypias in the right lobe. One year after substitution therapy, a palpable tumour on the left side of the remnant tissue was found, significantly growing with time, presented as hot nodule on 99mTc-sestamibi scan and conclusive with Hürthle cell adenoma with marked cellularity on FNAB. Tumorectomy was performed and well-differentiated Hürthle cell carcinoma detected. The patient received ablative dose of 100 mCi 131I. No signs of metastatic disease are present up to date.ConclusionsThe differences between Hürthle cell adenomas and Hürthle cell carcinomas could be clearly made only by histopathological evaluation. Patients with cytological diagnosis of Hürthle cell neoplasms should proceed to total thyroidectomy, especially if tumour size is > 1cm, FNAB findings comprise cellular atypias and/or multiple bilateral nodules are detected in the thyroid gland.

A Unique Case of Bilateral Hürthle Cell Adenoma in an Adolescent

“…Pathologists in the past were reluctant to classify HCN as benign due to the known aggressive nature of HCC [60], but subsequent studies have demonstrated that histologic criteria can reliably differentiate HCA from HCC [61]. A case of HCA with atypia and follicular adenoma recurring as HCC suggested that total thyroidectomy be performed for large HCA >1 cm with cellular atypia, or if multiple bilateral nodules are detected [62]. We agree with the approach of total thyroidectomy for those with bilateral nodules, as our patient also had bilateral nodules detected at the initial visit but underwent two separate hemithyroidectomies.…”